In an obituary posted on her websiteshortly after her death, it was revealed that she is survived by Tam O'Shaughnessy, her partner of nearly 30 years.

The pair met while playing tennis when they were 12 years old and stayed in contact as Dr Ride became an astronaut and Dr O'Shaughnessy became a professional tennis player. Both later earned doctorate science degrees.

Dr Ride's sister, Bear Ride, and a spokesman for Sally Ride Science, the organisation led by Dr Ride and Dr O'Shaughnessy, later reportedly confirmed that the astronaut – who was once married – was gay.

"I hope it makes it easier for kids growing up gay that they know that another one of their heroes was like them," Dr Ride's sister told the BuzzFeed news website.

Dr Ride was 32 when in 1983 she became the first American woman to fly to space alongside four other crew members.

The five astronauts flew aboard Challenger, the ill-fated space shuttle which exploded in Cape Canaveral 73 seconds after take-off three years later.

A year after her first voyage she successfully returned to space in the same shuttle for an eight-day mission.

She was training for a third mission when disaster struck the Challenger shuttle at the Kennedy Space Centre in 1986 and the programme was suspended.

Six of her colleagues died in the disaster and Dr Ride, a star physicist who was accepted onto the space programme in 1978 after answering an advertisement for astronauts in a newspaper, was a member of the team that investigated the incident.

Charles Bolden, a former astronaut who is now the administrator of Nasa, said she would be missed but "her star will always shine brightly".

"Sally Ride broke barriers with grace and professionalism – and literally changed the face of America's space programme," he added.

Dr Ride married fellow astronaut Steven Hawley in 1982 but the marriage ended in 1987.